JP2004215462A - Motor controller and printer having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constitution capable of simply and smoothly transferring the exciting mode of a stepping motor during driving. <P>SOLUTION: After the switching designation point of the exciting mode provided on the way of an acceleration period and a deceleration period during the driving of the motor is sensed, the exciting mode is transferred from a quarter step to a half/full step based on the coincidence signal of a coincidence signal generator circuit for detecting a point for bringing a phase position in the exciting mode, immediately before the transfer and a phase position in the exciting mode after the transfer into coincidence. The exciting mode can be smoothly transferred while step-out in association with the transfer of the exciting mode is prevented in association with the transfer of the exciting mode. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a motor control device that controls driving of a stepping motor (hereinafter, also simply referred to as a motor) and a printer including the same.
[0002]
[Prior art]
Generally, when the motor is started, the rotation speed is gradually increased, and then the motor is rotated at a constant speed. After a certain time, the motor starts decelerating and stops. Therefore, there are three sections from the start to the stop of the motor: an acceleration section, a constant velocity section, and a deceleration section.
[0003]
As is well known, the rotation speed of the motor is determined by the excitation mode and the pulse period. For example, in the case of a four-phase motor, the excitation modes include a W1-2-phase excitation mode of a quarter step (quarter step), a half-step 1-2-phase excitation mode, a two-phase excitation mode, and a full-step single-phase excitation mode. There is a two-phase excitation mode and the like. In the half-step excitation mode, the step angle progressing in one pulse is twice the quarter step excitation mode, and in the full step excitation mode, the step angle progressing in one pulse is four times the quarter step excitation mode. It is twice.
[0004]
Therefore, when the pulse cycle is constant, the rotation speed increases as the step angle increases. For example, when a transition is made from the quarter step excitation mode to the half step excitation mode, the rotation speed is doubled. Further, when the mode is shifted from the half-step excitation mode to the full-step excitation mode, the rotation speed is further doubled.
[0005]
As described above, by shifting the excitation mode, the rotation speed can be increased. Conversely, if the mode is shifted from the full-step excitation mode to the half / quarter-step excitation mode, the rotation speed can be reduced.
[0006]
When the excitation mode is constant, the rotation speed can be accelerated or decelerated by changing the pulse period.
[0007]
Such a stepping motor is applied to various devices, but may be used as a drive motor for a paper feeding operation (paper feed) in an ink jet printer (ink jet printer), for example. In such a paper feeding operation, in the initial stage of the paper feeding operation, it is necessary to gradually rotate the motor at a relatively small step angle where the torque is large. It is required to rotate the motor at a high speed in order to execute the sheet feeding operation.
[0008]
Also, in the paper feeding operation at the time of printing, the required speed of the paper feeding operation is variously varied depending on whether or not the printing mode is set, for example, a full color (fine) mode. As described above, the stepping motor of the printer is required to have a torque and various speeds according to the paper feeding status.
[0009]
At this time, in an operation state in which paper feeding is required at the finest pitch, it is necessary to adjust the pitch to the step angle of the motor. On the other hand, if the motor is rotated at a high speed with the step angle determined in this way, the required performance is increased, so that an expensive motor is required.
[0010]
Therefore, in order to use the motor efficiently, even during a series of acceleration sections and deceleration sections, the excitation mode of the motor is smoothly changed to enable both the operation at a fine step angle and the high-speed operation at a large step angle. It is desirable to make it correspond.
[0011]
In this regard, Japanese Patent Application Laid-Open No. 5-300797 proposes a method in which the excitation mode is smoothly shifted during driving of the motor without suddenly changing the rotation speed.
[0012]
More specifically, the CPU (Central Processing Unit) adjusts the pulse rate, that is, the pulse period, that is, makes the ratio of the step angle per pulse to the pulse period constant to prevent the speed from changing suddenly, and to set the excitation mode. A method for executing the transition of the above is disclosed.
[0013]
[Patent Document 1]
JP-A-5-300797 (FIG. 1, p3 to p5)
[0014]
[Problems to be solved by the invention]
However, in the above-described method, there is a problem that the CPU needs to execute a pulse period adjusting operation, which increases the load on the CPU and complicates the control.
[0015]
The present invention provides a motor control device for a stepping motor that can easily and smoothly shift the excitation mode of the motor during driving by a simple control method without suddenly changing the speed, and a printer including the same. The purpose is to:
[0016]
[Means for Solving the Problems]
A printer according to the present invention includes a stepping motor used for transporting a transfer body, and a motor control device for driving the stepping motor according to a predetermined speed pattern. The motor control device includes a storage unit, a pulse generation unit, an excitation mode control unit, a coincidence signal generation unit, a timing adjustment unit, and a transition instruction signal generation circuit. The storage unit stores in advance data indicating the speed pattern. The pulse generation unit generates a pulse signal at intervals according to the speed pattern based on the data read from the storage unit. The excitation mode control unit shifts from the first excitation mode that advances at the first step angle to the second excitation mode that advances at the second step angle in response to the shift instruction signal during driving of the stepping motor, and , The excitation current of the stepping motor is controlled according to the input of the pulse signal from the pulse generation unit based on one of the first and second excitation modes. The coincidence signal generation circuit outputs the pulse signal based on the first and second excitation modes every predetermined number of input times, and determines the phase position of the first excitation mode and the phase position of the second excitation mode immediately before the transition. Generate a match signal indicating a match. The timing adjuster outputs the input shift instruction signal to the excitation mode controller in response to the input of the match signal from the match signal generator. The transition instruction signal generation circuit generates a transition instruction signal to the timing adjustment unit at least once in the middle of at least one of the preset acceleration section and deceleration section of the stepping motor. The transition instruction signal generation circuit has a counter for counting the input pulse signal a predetermined number of times and outputting a transition instruction signal. The excitation mode control unit has a cycle counter and a current control unit. The period counter periodically selects one of the plurality of phase positions in response to the pulse signal. The current control unit controls the excitation current of the stepping motor according to the phase position selected by the cycle counter and one of the first and second excitation modes. In the acceleration section of the stepping motor, the second excitation mode includes a first mode in which the second step angle is twice the first step angle in the first excitation mode, and a second step angle in the second excitation mode. At least one of the second mode corresponding to four times the step angle of 1 is included. In the first excitation mode, at least one of the polarity and the level of the excitation current of the stepping motor is different in each of the plurality of phase positions. In the first mode of the second excitation mode, at least one of the polarity and the level of the excitation current of the stepping motor is different in each of a set of two consecutive phase positions. . In the second mode of the second excitation mode, at least one of the polarity and the level of the excitation current of the stepping motor is different in each of a set of four consecutive phase positions. . In each of the first and second modes, the polarity and level of the exciting current of the stepping motor are set the same at each phase position included in the same set. In the deceleration section of the stepping motor, the first excitation mode includes a first mode in which a first step angle of the first excitation mode is twice as large as a second step angle of the second excitation mode. One step angle includes at least one of the second mode in which the step angle is four times the second step angle. In the first mode of the first excitation mode, at least one of the polarity and the level of the excitation current of the stepping motor is different in each of a pair of two consecutive phase positions. . In the second mode of the first excitation mode, at least one of the polarity and the level of the excitation current of the stepping motor is different in each of a set of four consecutive phase positions. . In the second excitation mode, at least one of the polarity and the level of the excitation current of the stepping motor is different in each of the plurality of phase positions. In each of the first and second modes of the first excitation mode, the polarity and level of the excitation current of the stepping motor are set the same at each phase position included in the same set.
[0017]
A motor control device according to the present invention is a motor control device for driving a stepping motor according to a predetermined speed pattern, and includes a storage unit, a pulse generation unit, an excitation mode control unit, a coincidence signal generation unit, And a timing adjustment unit. The storage unit stores in advance data indicating the speed pattern. The pulse generation unit generates a pulse signal at intervals according to the speed pattern based on the data read from the storage unit. The excitation mode control unit shifts from the first excitation mode that advances at the first step angle to the second excitation mode that advances at the second step angle in response to the shift instruction signal during driving of the stepping motor, and , The excitation current of the stepping motor is controlled according to the input of the pulse signal from the pulse generation unit based on one of the first and second excitation modes. The coincidence signal generation unit is output every predetermined number of times of input of the pulse signal based on the first and second excitation modes, and the phase position of the first excitation mode and the phase position of the second excitation mode immediately before the transition are set. Generate a match signal indicating a match. The timing adjuster outputs the input shift instruction signal to the excitation mode controller in response to the input of the match signal from the match signal generator.
[0018]
Preferably, the apparatus further includes a transition instruction signal generation circuit that generates a transition instruction signal to the timing adjustment unit when a preset number of input pulse signals has elapsed.
[0019]
In particular, the transition instruction signal generation circuit generates the transition instruction signal at least once in the middle of at least one of the acceleration section and the deceleration section of the stepping motor.
[0020]
In particular, the transition instruction signal generation circuit has a counter for counting the input pulse signal a preset number of times and outputting a transition instruction signal.
[0021]
Preferably, the excitation mode control unit includes a cycle counter and a current control unit. The period counter periodically selects one of the plurality of phase positions in response to the pulse signal. The current control unit controls the excitation current of the stepping motor according to the phase position selected by the cycle counter and one of the first and second excitation modes.
[0022]
In particular, in the acceleration section of the stepping motor, the second excitation mode includes a first mode in which the second step angle is twice the first step angle of the first excitation mode, and a second step angle. Include at least one of the second mode corresponding to four times the first step angle. In the first excitation mode, at least one of the polarity and the level of the excitation current of the stepping motor is different in each of the plurality of phase positions. In the first mode of the second excitation mode, at least one of the polarity and the level of the excitation current of the stepping motor is different in each of a set of two consecutive phase positions. . In the second mode of the second excitation mode, at least one of the polarity and the level of the excitation current of the stepping motor is different in each of a set of four consecutive phase positions. . In each of the first and second modes, the polarity and level of the exciting current of the stepping motor are set the same at each phase position included in the same set.
[0023]
In particular, in the deceleration section of the stepping motor, the first excitation mode includes a first mode in which a first step angle of the first excitation mode is twice as large as a second step angle of the second excitation mode. , And the second mode in which the first step angle is equal to four times the second step angle. In the first mode of the first excitation mode, at least one of the polarity and the level of the excitation current of the stepping motor is different in each of a pair of two consecutive phase positions. . In the second mode of the first excitation mode, at least one of the polarity and the level of the excitation current of the stepping motor is different in each of a set of four consecutive phase positions. . In the second excitation mode, at least one of the polarity and the level of the excitation current of the stepping motor is different in each of the plurality of phase positions. In each of the first and second modes of the first excitation mode, the polarity and level of the excitation current of the stepping motor are set the same at each phase position included in the same set.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions have the same reference characters allotted, and description thereof will not be repeated.
[0025]
FIG. 1 is a conceptual diagram of a motor control device 10 according to an embodiment of the present invention and a stepping motor 80 used for transporting a transfer body such as paper feeding.
[0026]
With reference to FIG. 1, the motor control device 10 includes a memory 15 having a speed pattern data table 40 in which information on a rotation speed pattern of a stepping motor 80 is stored, and a speed pattern data table 40 stored in the memory 15. A processor 20 that receives necessary data information TD and outputs necessary data and the like, and a motor control circuit 30 that generates a control signal group DVS for driving the stepping motor 80 based on the input of data and the like from the processor 20 And a motor driver IC 70 that controls the amount and direction of the exciting current supplied to excite the stepping motor 80 in response to the input of the control signal group DVS output from the motor control circuit 30.
[0027]
Further, the processor 20 outputs a control signal PEN (“1”) to the motor control circuit 30 at the start of the drive control of the stepping motor 80, and also outputs the mode signals (PSM, FSM) for selecting transition to three types of excitation modes. , HSM). In this specification, the high voltage level and the low voltage level of a signal are represented as “1” and “0”, respectively.
[0028]
The motor control circuit 30 generates a pulse signal CPS that generates a pulse signal CPS corresponding to the input of the frequency data CD output from the processor 20 based on the data information TD, and a pulse signal CPS output from the pulse generation circuit 50. And a motor drive control signal generation circuit 60 that generates a control signal group DVS for driving the motor in response.
[0029]
FIG. 2 is a diagram showing a series of operations of the stepping motor 80 for acceleration, constant speed, and deceleration.
[0030]
Referring to FIG. 2, the vertical axis represents the set speed of stepping motor 80, and the horizontal axis represents the number of steps from the start of motor drive control in pulse signal CPS.
[0031]
When the drive control of the motor 80 is started, the motor 80 operates as an acceleration section from step numbers S0 to S3. In addition, the motor 80 operates as a constant speed section from step numbers S3 to S4. Further, the motor 80 operates as a deceleration section from step numbers S4 to S6. At the time of the step number S6, the motor 80 stops. The pulse signal generation interval is set in accordance with the case where the motor 80 is constantly driven in quarter steps without considering the transition of the excitation mode during driving. Therefore, the rotation amount of the motor 80 in a series of operations corresponds to the product of the step angle and the total number of steps in the quarter step excitation mode. Note that, in the present example, as an example, the number of steps S0 will be described as “0”.
[0032]
Further, in each of the acceleration section and the deceleration section, an excitation mode switching instruction point is provided midway. In FIG. 2, each of step numbers S1 and S5 is shown as a switching instruction point of the excitation mode.
[0033]
For example, in the initial stage of paper feeding used in the paper feeding mechanism of the printer, by driving in a quarter step having a relatively high torque in order to prevent slipping, the stepping motor is gradually rotated at a small step angle at a low speed. Accelerate. Further, after the feeding is stabilized and the danger of slip is reduced, it is necessary to rotate the motor at high speed.Therefore, during the acceleration period, the excitation mode is set to half-step or half-step to increase the step angle. Move to full step.
[0034]
Further, in the stop stage, in order to improve the stop accuracy, the motor is gradually decelerated, and the excitation mode is again shifted to the quarter step so as to return to a small step angle from the middle of the deceleration section. In this way, a stable and high-speed sheet feeding operation can be executed by efficiently utilizing the motor performance.
[0035]
Hereinafter, in the present embodiment, as an example, a configuration in which the excitation mode is smoothly shifted in the acceleration and deceleration sections will be described.
[0036]
FIG. 3 is a conceptual diagram of motor control circuit 30 according to the embodiment of the present invention.
Referring to FIG. 3, motor control circuit 30 according to the embodiment of the present invention includes a pulse generation circuit 50 and a motor drive control signal generation circuit 60.
[0037]
The pulse generation circuit 50 is activated in response to the input of the control signal PEN, and generates a pulse signal CPS based on frequency data CD for instructing the rotation speed of the motor. Specifically, the pulse signal CPS is generated at intervals according to the designated motor speed based on the step angle in the quarter step excitation mode as described above.
[0038]
The motor drive control signal generation circuit 60 includes a phase counter 100, a phase table 110, a coincidence signal generation circuit 120, a switching step number setting circuit 130, a counter 140, a coincidence circuit 150, and an AND circuit 160.
[0039]
The phase counter 100 generates a binary 4-bit phase signal PP (3: 0) that is incremented by one in response to the input of the pulse signal CPS input from the pulse generation circuit 50. In this specification, a signal (p: 0) indicates a (p + 1) -bit signal in binary notation. The same applies to the following.
[0040]
The phase table 110 generates a control signal group DVS according to the phase signal PP (3: 0) in the selected excitation mode. In addition, when the excitation mode shifts, the phase table 110 responds to the input of the shift timing signal SP and responds to the input of the mode signals FSM, QSM, and HSM in three types of excitation modes (a quarter step, a half step, and a full step). Step 1).
[0041]
The coincidence signal generation circuit 120 detects, based on the input phase signal PP (3: 0), a point at which a phase position described later in the excitation mode immediately before the transition coincides with a phase position in the excitation mode after the transition. To generate a coincidence signal SAE.
[0042]
The match signal generation circuit 120 has match circuits 200 and 201 and an OR circuit 210.
[0043]
Matching circuit 200 is activated in response to mode signal FSM ("1") for selecting the transition to the full step, and outputs lower-order bit phase signal PP (1: 0) of phase signal PP (3: 0). ) Is compared with the data signal “00”. If they match, the control signal FS is output as "1". Specifically, the coincidence circuit 200 sets the control signal FS to “1” when the phase position in the excitation mode of the quarter step immediately before the transition matches the phase position in the excitation mode of the full step.
[0044]
The coincidence circuit 201 is activated in response to the mode signal HSM (“1”) for selecting the transition to the half step, and the lower-order bit phase signal PP (0) of the phase signal PP (3: 0) is output. ) Is compared with the data signal “0”. If they match, the control signal HS is output as "1". Specifically, the coincidence circuit 201 sets the control signal HS to (“1”) when the phase position in the quarter-step excitation mode immediately before the transition matches the phase position in the full-step excitation mode.
[0045]
The OR circuit 210 responds to the input of the input control signal FS (“1”), HS (“1”) or the mode signal QSM (“1”) for selecting the excitation mode of the quarter step, and performs an OR logical operation on the OR signal. The result is output as a coincidence signal SAE ("1").
[0046]
In the switching step number setting circuit 130, the number of steps for executing the transition instruction of the excitation mode is input in advance, and the number of steps is transmitted to the counter 140 in response to the input of the control signal AP or DP output from the processor 20. Is entered. The counter 140 counts down the number of steps input in synchronization with the input pulse signal CPS. The coincidence circuit 150 compares the counter count ACS (DCS), which is counted down by the counter 140 and output, with data “0”. When the counter number ACS (DCS) becomes “0”, the coincidence circuit 150 generates the control signal PAE (“1”) indicating that the step number of the pulse signal CPS has reached the above-described excitation mode switching instruction point. I do.
[0047]
The AND circuit 160 generates an AND logical operation result as the transition timing signal SP (“1”) in response to the coincidence signal SAE and the control signal PAE being both set to “1”. In response to the input of the transition timing signal SP (“1”), the phase table 110 executes the transition to the selected excitation mode based on the mode signal (QSM, HSM, FSM). That is, the transition timing signal SP is set to “1” when the phase position in the excitation mode immediately before the transition and the phase position in the excitation mode after the transition coincide with reaching the excitation mode switching instruction point.
[0048]
FIG. 4 is a data pattern diagram of the control signal group DVS output from the phase table 110 according to the phase signal PP (3: 0).
[0049]
FIG. 4A is a data pattern diagram of the control signal group DVS in the excitation mode of the quarter step. FIG. 4B is a data pattern diagram of the control signal group DVS in the half-step excitation mode. FIG. 4C is a data pattern diagram of the control signal group DVS in the full-step excitation mode.
[0050]
Referring to FIG. 4A, in this example, the phase positions (0) to (15) (hereinafter, also simply referred to as phases (0) to (15)) are 4-bit phase signals PP (3: 0). The phase positions (0) to (15) indicate the step positions of the stepping motor. Specifically, when the phase signal PP is “0000”, the control signal group DVS corresponding to the phase position (0) in FIG. 4A is referred to. Similarly, when the phase signal PP is “0001”, the control signal group DVS at the phase position (1) is referred to. In the case of another phase signal PP, the control signal group DVS is referred to according to the same method. Accordingly, in the quarter step excitation mode, the phase position of the stepping motor advances one by one in response to the input of the phase signal PP. For example, when the motor is currently at the phase position (0), the control signal group DVS at the phase position (0) is referred to, and the motor advances to the phase position (1).
[0051]
On the other hand, in the half step, in response to the input of the phase signal PP twice, the phase signal PP advances two by two to the phase position of the stepping motor.
[0052]
Further, in the full step, in response to the input of the phase signal PP four times, the phase signal PP advances four by four to the phase position of the stepping motor.
[0053]
Here, the control signal group DVS will be described in detail.
In each excitation mode, the control signal group DVS includes control signals PH1 and PH2 indicating the polarity of the excitation current of the stepping motor, and control signals I01, I11, I02 and I12 indicating the amount of current. The combination of control signal PH1 and I01, I11 indicates the polarity and amount of the exciting current of one phase. Specifically, “0” and “1” of the control signal PH1 correspond to the positive polarity and the negative polarity of the corresponding exciting current, respectively, and (I01, I11) = (00), The four levels of current amounts (01), (10), and (11) are shown. Similarly, the polarity and amount of the exciting current of the other phase are indicated by the combination of control signal PH2 and I02 and I12.
[0054]
As described above, in each excitation mode, one of the 16 phase positions (0) to (15) is periodically selected according to the phase signal PP (3: 0), and the control signals PH1, PH2 and control signals I01, I11, I02, and I12 are determined.
[0055]
As shown in FIG. 4A, in the quarter step, at least at each phase position, that is, each time the phase signal PP (3: 0) is incremented by one in response to the input of the pulse signal CPS, at least At least one of the polarity and the amount of the exciting current is switched in one phase, and the stepping motor rotates by one phase position.
[0056]
On the other hand, in the half step shown in FIG. 4B, a set is formed for every two consecutive phase positions, and in each set, the polarity and amount of the exciting current of each phase are the same. . Therefore, each time the phase signal PP (3: 0) changes by two, that is, each time two pulse signals CPS are input, at least one of the polarity and the current amount of the exciting current is switched in at least one phase. Then, the stepping motor rotates to advance two phase positions.
[0057]
Similarly, at the time of the full step shown in FIG. 4C, a set is formed for every four consecutive phase positions, and the polarity and amount of the exciting current of each phase are the same in each set. Therefore, each time the phase signal PP (3: 0) changes by four, that is, each time four pulse signals CPS are input, at least one of the polarity and the amount of the exciting current is switched in at least one phase. Then, the stepping motor rotates and the phase position advances by four.
[0058]
By setting the excitation mode by controlling the phase current of the stepping motor by the method shown in FIG. 4, the step angle in the quarter step is unified without considering switching of the excitation mode during driving. By calculation, the number of generations and the generation interval of the pulse signal CPS can be set. As a result, the speed pattern data table stored in the memory 15 for generating the pulse signal can be reduced.
[0059]
Here, for example, consider the transition of the excitation mode from quarter step to half step.
[0060]
As can be seen from FIG. 4, in order to shift from the quarter step to the half step or the full step, depending on the phase position immediately before shifting the excitation mode, there are cases where the shift can be made immediately and cases where the shift cannot be made immediately.
[0061]
FIG. 5 is a diagram illustrating a phase position at which a direct transition from a quarter step to a half step is possible and a phase position at which a direct transition is impossible and adjustment is required.
[0062]
Referring to FIG. 5A, the phase positions at which the direct transition from the quarter step to the half step is possible are the even-numbered phase positions of phases (0), (2),... (14).
[0063]
On the other hand, with reference to FIG. 5B, the phase positions at which the direct transition from the quarter step to the half step is impossible are the odd-numbered phase positions of phases (1), (3),. It is. If the excitation mode is shifted at this phase position, the stepping motor loses synchronism. Therefore, in this case, the step-out can be prevented by shifting to the excitation mode after proceeding to the next phase position, that is, the even-numbered phase position.
[0064]
FIG. 6 is a diagram illustrating a phase position at which a direct transition from a quarter step to a full step is possible and a phase position at which a direct transition is impossible and adjustment is required.
[0065]
Referring to FIG. 6A, the phase positions at which the direct transition from the quarter step to the full step is possible are the phase positions of phases (0), (4), (8), and (12). At other phase positions, a direct transition is not possible.
[0066]
Referring to FIG. 6B, in a phase position where direct shift is not possible, step-out can be prevented by shifting to a phase position where direct shift is possible and then shifting.
[0067]
Specifically, at the phase position of the phase (1), the process proceeds to the phase position of the phase (4) by three steps in the quarter step, and then shifts to the full step.
[0068]
At the phase position of the phase (2), the process proceeds to the phase position of the phase (4) by two steps in the quarter step, and then the transition to the full step is executed.
[0069]
At the phase position of the phase (3), the process proceeds to the phase position of the phase (4) in the quarter step by one step and then shifts to the full step.
[0070]
For other phase positions that cannot be directly shifted, the excitation mode is shifted without step-out by executing the shift to the full step after proceeding to the shiftable phase position according to the same method. be able to.
[0071]
On the other hand, in the transition from the full step or half step to the quarter step, the transition can be executed immediately because the phase position of the quarter step has all the phase positions of the full step or half step.
[0072]
FIG. 7 is a flowchart showing a procedure of control processing of motor control circuit 30 according to the present embodiment in the motor operation shown in FIG. In this example, as an example, it is assumed that the switching step number setting circuit 130 is set in advance so that an instruction to change the excitation mode is output at the step numbers S1 and S5 shown in FIG. Specifically, it is assumed that the number of steps S1-S0 is set in the counter 140 in the switching step number setting circuit 130 in response to the input of the control signal AP input at the start of the acceleration section. Also, it is assumed that the number of steps S5-S4 is set in the counter 140 in response to the input of the control signal DP input at the start of the deceleration section.
[0073]
Referring to FIGS. 2, 3 and 7, at the time of step number S0 ("0"), the idle state, that is, the stepping motor is in a non-rotation state (step P0).
[0074]
Next, when the drive control of the stepping motor 80 starts, the control signal PEN (“1”) is output from the processor 20 as described above. In response to this, the pulse generation circuit 50 outputs a pulse signal CPS corresponding to the frequency data CD. Accordingly, the rotation speed of the stepping motor 80 increases according to the acceleration # 1 corresponding to the pulse signal CPS. At the same timing, the control signal AP is input from the processor 20 in response to the start of the acceleration section. Accordingly, the counter 140 sets the number of steps S1-S0 in the counter 140, and counts down until the counter number ACS becomes “0” (step P1).
[0075]
Next, when the counter number ACS becomes “0”, that is, when the step number of the pulse signal CPS becomes S1, the matching circuit 150 generates the control signal PAE (“1”) as described above.
[0076]
With the generation of the control signal PAE ("1"), an instruction to shift from the quarter step to the half / full step excitation mode is to be issued. However, direct shift is impossible depending on the phase position of the motor 80. Need to adjust. That is, the phase position is adjusted when shifting the excitation mode until the shift timing signal SP becomes "1" (step P2). Specifically, the process proceeds in quarter steps until the coincidence signal SAE becomes “1”.
[0077]
For example, when executing the shift to the half step, if the least significant bit of the phase signal PP is “0”, in other words, the current phase position is the phase (0), (2), (4), .. Can directly transition from the quarter step to the half step in response to the input of the next pulse signal as described above. Therefore, the matching circuit 201 generates the control signal HS (“1”) in response to the least significant bit of the phase signal PP becoming “0”.
[0078]
On the other hand, when executing the transition to the full step, when the lower two bits of the phase signal PP are “00”, in other words, the current phase position is the phase (0), (4), (8), In the case of (12), it is possible to directly shift from the quarter step to the full step in response to the input of the next pulse signal as described above. Therefore, matching circuit 200 generates control signal FS (“1”) in response to the lower bit of phase signal PP becoming “00”.
[0079]
Accordingly, the coincidence signal generation circuit 120 outputs the generated control signal HS (“1”) or FS (“1”) as the coincidence signal SAE.
[0080]
The phase table 110 shifts the excitation mode from the quarter step to the full / half step in response to the shift timing signal SP generated from the AND circuit 160 to which the coincidence signals SAE and PAE are input becoming “1” ( Step P2 #). FIG. 2 shows that the transition to the excitation mode has been executed at the step number S2.
[0081]
Next, in Step P3, the motor 80 increases the rotation speed in accordance with the acceleration # 2 according to the pulse signal CPS (Step P3).
[0082]
Next, after a predetermined acceleration step has elapsed, the stepping motor enters a constant speed state in step number S3 in FIG. 2 (step P4).
[0083]
Next, in the step number S4 after the lapse of the constant speed section, the stepping motor 80 reduces the rotation speed according to the deceleration # 1 corresponding to the pulse signal CPS. At the same timing, the control signal DP is input from the processor 20 in response to the start of the deceleration section. Accordingly, the counter 140 sets the number of steps S5-S4 in the counter 140, and counts down until the counter count DCS becomes "0" (step P5).
[0084]
Next, when the counter count DCS becomes “0”, that is, when the step number of the pulse signal CPS becomes S5, the coincidence circuit 150 generates the control signal PAE (“1”) as described above.
[0085]
In response to the control signal PAE (“1”), an attempt is made to shift from the quarter step to the half / full step excitation mode. Until the shift timing signal SP becomes “1”, the phase position at which the excitation mode shifts is shifted. Is adjusted (step P6).
[0086]
Here, as described above, since the transition of the excitation mode from the full / half step to the quarter step can be directly performed at any phase position, the control signal QSM (“1”) for instructing the mode change to the quarter step is provided. Accordingly, match signal SAE is set to “1”. Along with this, the transition timing signal SP is immediately set to "1", and the excitation mode is transitioned (step P6 #). That is, in this example, there is no need to adjust the phase position.
[0087]
Next, in Step P7, the stepping motor lowers the rotation speed according to the deceleration # 2 according to the pulse signal CPS.
[0088]
Next, the stepping motor is stopped at the step number S6 after the elapse of the predetermined deceleration step (step P8).
[0089]
As described above, according to the stepping motor drive device of the present invention, the excitation mode of the stepping motor is changed after the excitation mode switching instruction point provided in advance in the acceleration section and the deceleration section during motor driving. Thus, the step angle can be changed smoothly. Therefore, the stepping motor can be driven with a fine step angle at the start of acceleration and before stopping, and at a large step angle during high-speed operation, so that operation that achieves both stable startup, high stopping accuracy, and high speed can be performed efficiently. It can be executed by utilizing it. In this example, the configuration in which the excitation mode is shifted in the acceleration section and the deceleration section has been described. However, the present invention is not limited to this, and it is also possible to shift in the constant speed section.
[0090]
FIG. 8 is a schematic block diagram showing the overall configuration of a printer provided with a stepping motor driving device according to the present invention.
[0091]
Referring to FIG. 8, personal computer 310 is a device that controls inkjet printer 380, and includes a USB control unit 311, an operation input unit 312, a command output unit 313, and a print data output unit 314.
[0092]
The operation input unit 312 receives a print instruction from a user. The print data output unit 314 is realized by a program and a CPU that executes the program, and outputs print data. The command output unit 313 is realized by a program and a CPU that executes the program, and outputs a paper feed command, a print start command, a print end command, and a paper discharge command. The USB control unit 311 outputs a print start command, a paper feed command, a print end command, a paper discharge command, and print data to the USB cable 315.
[0093]
An ink jet printer 380 shown as a typical example of a printer having a stepping motor driving device according to the present invention includes a control unit 320, a carrier motor 328, a paper feed motor 329, a carrier 332, a feed roller 330, and a paper ejection. And a roller 331.
[0094]
The control unit 320 includes a CPU 321, a USB control unit 322, a ROM 323, and an ASIC 324. The ROM 323 stores a program executed by the CPU 321. The USB control unit 322 receives a print start command, a paper feed command, print data, a print end command, and a paper discharge command sent from the personal computer 310 via the USB cable 315.
[0095]
The ASIC 324 includes a carrier motor control unit 325, a paper feed motor control unit 326, and a print control unit 327. The carrier motor control unit 325 controls driving of the carrier motor 328. The carrier motor 328 moves the carrier 332 in the main scanning direction.
[0096]
An ink cartridge 333 that supplies ink to the print head 334 is mounted on the carrier 332. The print control unit 327 controls printing of the print head 334 of the ink cartridge 333 mounted on the carrier 332.
[0097]
The feed motor control unit 326 controls driving of the feed motor 329. The paper feed motor 329 transports the print paper in the sub-scanning direction. The feed motor 329 drives the feed roller 330, and when the feed roller 330 rotates, this rotation is transmitted to the discharge roller 331 via the belt, and the discharge roller 331 also rotates. When the printing of one line is completed, the sheet feeding motor 329 conveys the printing paper in the sub-scanning direction in order to print the next line.
[0098]
When receiving the sheet feed command, the CPU 321 instructs the sheet feed motor control unit 326 to drive the sheet feed motor 329.
[0099]
Upon receiving the print start command, the CPU 321 instructs the carrier motor control unit 325 to drive the carrier motor 328 to move the carrier 332 from the home position to the print start position.
[0100]
Upon receiving the print data, the CPU 321 instructs the carrier motor control unit 325 to drive the carrier motor 328 to instruct the print control unit 327 while moving the carrier 332 in the main scanning direction. The print data is printed by ejecting ink to the print head 334 of the attached ink cartridge 333.
[0101]
When printing of one line is completed, the CPU 321 instructs the carrier motor control unit 325 to stop the carrier motor 328 and stop the carrier 332. Then, the CPU 321 instructs the paper feed motor control unit 326 to drive the paper feed motor 329 to move the print paper in the sub-scanning direction only between the lines.
[0102]
When receiving the print end command, the CPU 321 instructs the carrier motor control unit 325 to stop the carrier motor 328 and stop the carrier 332.
[0103]
Further, when receiving the paper discharge command, the CPU 321 instructs the paper feed motor control unit 326 to drive the paper feed motor 329 to discharge the print paper, and instructs the carrier motor control unit 325 to output the carrier. The motor 328 is driven to move the carrier 332 to the home position.
[0104]
The stepping motor 80 is used as the sheet feeding motor 329. As described above, in order to perform the sheet feeding operation stably and at a high speed, it is desirable to shift the speed pattern setting and the excitation mode as shown in FIG. Therefore, by configuring the feed motor control unit 326 with the drive control device of the stepping motor according to the present invention, that is, the motor control device 10 shown in FIG. 1, the feed motor 329 can be stably manufactured without increasing the cost. In addition, a high-speed paper feeding operation can be performed. It should be noted that the speed pattern setting and the excitation mode switching shown in FIG. 2 can be optimally set by subdividing for each sheet discharging operation and other operations.
[0105]
Further, the carrier motor control unit 325 can be configured by a motor control device for a stepping motor according to the present invention, and can control the drive of the carrier motor 328 configured by the stepping motor. Alternatively, it is also possible to drive and control another stepping motor provided in the ink jet printer 380 by driving control of the stepping motor according to the present invention.
[0106]
The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any transition within the scope and meaning equivalent to the terms of the claims.
[0107]
【The invention's effect】
As described above, according to the motor control device for a stepping motor according to the present invention, the shift instruction signal for instructing the shift of the excitation mode is output when the phase positions of the first and second excitation modes match during motor driving. It can be input to the excitation mode control unit. Therefore, it is possible to smoothly shift to the excitation mode while preventing step-out at the time of shifting to the excitation mode. Therefore, at the start and stop of acceleration, the motor can be driven at a large step angle during a high-speed operation with a fine step angle, so that a single motor can achieve stable startup, high stop accuracy, and high-speed operation at the same time. Can be efficiently utilized and executed.
[0108]
Further, according to the printer having such a stepping motor, the sheet feeding operation and the sheet discharging operation can be executed stably and at high speed without increasing the cost of the stepping motor.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a motor control device 10 according to an embodiment of the present invention and a stepping motor 80 used for transporting a transfer body such as paper feed.
FIG. 2 is a diagram showing a series of operations of acceleration, constant speed, and deceleration of a stepping motor 80.
FIG. 3 is a conceptual diagram of a motor control circuit 30 according to the embodiment of the present invention.
FIG. 4 is a data pattern diagram of a control signal group DVS output from a phase table 110 according to a phase signal PP (3: 0).
FIG. 5 is a diagram illustrating a phase position at which a direct transition from a quarter step to a half step is possible and a phase position at which a direct transition is impossible and adjustment is required.
FIG. 6 is a diagram illustrating a phase position at which a direct transition from a quarter step to a full step is possible and a phase position at which a direct transition is impossible and adjustment is required.
FIG. 7 is a flowchart showing a procedure of control processing of motor control circuit 30 according to the present embodiment.
FIG. 8 is a schematic block diagram illustrating the overall configuration of a printer including a stepping motor driving device according to the present invention.
[Explanation of symbols]
Reference Signs List 10 motor control device, 15 memory, 20 processor, 30 motor control circuit, 40 speed pattern table, 50 pulse generation circuit, 60 motor drive control signal generation circuit, 70 motor driver IC, 80 stepping motor.

Claims (8)

A stepping motor used to transport the transfer body, and a motor control device for driving the stepping motor according to a predetermined speed pattern,
The motor control device,
A storage unit that stores data indicating the speed pattern in advance,
A pulse generation unit that generates a pulse signal at intervals according to the speed pattern, based on the data read from the storage unit;
While the stepping motor is being driven, a transition is made from a first excitation mode that proceeds at a first step angle to a second excitation mode that proceeds at a second step angle in response to a transition instruction signal, and the first and the second modes are shifted. An excitation mode control unit for controlling an excitation current of the stepping motor in response to the input of the pulse signal from the pulse generation unit based on one of the second excitation modes;
The pulse signal is output every predetermined number of times of inputting the pulse signal based on the first and second excitation modes, and the phase position of the first excitation mode and the phase position of the second excitation mode immediately before the transition match. A match signal generation unit that generates a match signal indicating that
In response to the input of the coincidence signal from the coincidence signal generation unit, a timing adjustment unit for outputting the input shift instruction signal to the excitation mode control unit,
A shift instruction signal generating circuit that generates the shift instruction signal to the timing adjustment unit at least once in the middle of at least one of an acceleration section and a deceleration section of the stepping motor, which is set in advance,
The transition instruction signal generation circuit has a counter for counting the input pulse signal a preset number of times and outputting the transition instruction signal,
The excitation mode control unit, in response to the pulse signal, a counter that periodically selects one of a plurality of phase positions,
A current control unit that controls an excitation current of the stepping motor according to the phase position selected by the counter and the one of the first and second excitation modes;
In the acceleration section of the stepping motor, the second excitation mode includes a first mode in which the second step angle is twice as large as the first step angle in the first excitation mode; A step angle of 2 includes at least one of a second mode corresponding to four times the first step angle,
In the first excitation mode, at each of the plurality of phase positions, at least one of the polarity and the level of the excitation current of the stepping motor is different,
In the first mode of the second excitation mode, the polarity and level of the excitation current of the stepping motor are set in each of a pair of continuous two of the plurality of phase positions. At least one is different,
In the second mode of the second excitation mode, the polarity and level of the excitation current of the stepping motor are set in each of a group of four consecutive phase positions. At least one is different,
In each of the first and second modes, the polarity and level of the exciting current of the stepping motor are set to be the same at each of the phase positions included in the same set,
In the deceleration section of the stepping motor, the first excitation mode is such that the first step angle of the first excitation mode is twice as large as the second step angle of the second excitation mode. 1, and at least one of a second mode in which the first step angle is four times the second step angle,
In the first mode of the first excitation mode, the polarity and level of the excitation current of the stepping motor are set for each of a pair of two consecutive phase positions. At least one is different,
In the second mode of the first excitation mode, the polarity and level of the excitation current of the stepping motor are set in each of a group of four consecutive phase positions. At least one is different,
In the second excitation mode, at each of the plurality of phase positions, at least one of the polarity and the level of the excitation current of the stepping motor is different,
In each of the first and second modes of the first excitation mode, the polarity and level of the excitation current of the stepping motor are set to be the same at each of the phase positions included in the same set. . A motor control device for driving a stepping motor according to a predetermined speed pattern,
A storage unit that stores data indicating the speed pattern in advance,
A pulse generation unit that generates a pulse signal at intervals according to the speed pattern, based on the data read from the storage unit;
While the stepping motor is being driven, a transition is made from a first excitation mode that proceeds at a first step angle to a second excitation mode that proceeds at a second step angle in response to a transition instruction signal, and the first and the second modes are shifted. An excitation mode control unit for controlling an excitation current of the stepping motor in response to the input of the pulse signal from the pulse generation unit based on one of the second excitation modes;
The pulse signal is output every predetermined number of times of inputting the pulse signal based on the first and second excitation modes, and the phase position of the first excitation mode and the phase position of the second excitation mode immediately before the transition match. A match signal generation unit that generates a match signal indicating that
A motor control device comprising: a timing adjustment unit configured to output the input transition instruction signal to the excitation mode control unit in response to the input of the coincidence signal from the coincidence signal generation unit. 3. The motor control device according to claim 2, further comprising a transition instruction signal generation circuit that generates the transition instruction signal to the timing adjustment unit when a preset number of times of input of the input pulse signal has elapsed. 4. The motor control device according to claim 3, wherein the transition instruction signal generation circuit generates the transition instruction signal at least once during at least one of an acceleration section and a deceleration section of the stepping motor. 5. 4. The motor control device according to claim 3, wherein the transition instruction signal generation circuit has a counter for counting the input pulse signal a preset number of times and outputting the transition instruction signal. 5. The excitation mode control unit, in response to the pulse signal, a period counter that periodically selects one of a plurality of phase positions,
3. The motor control according to claim 2, further comprising: a current control unit that controls an excitation current of the stepping motor according to the phase position selected by the cycle counter and the one of the first and second excitation modes. 4. apparatus. In the acceleration section of the stepping motor, the second excitation mode includes a first mode in which the second step angle is twice as large as the first step angle in the first excitation mode; A step angle of 2 includes at least one of a second mode corresponding to four times the first step angle,
In the first excitation mode, at each of the plurality of phase positions, at least one of the polarity and the level of the excitation current of the stepping motor is different,
In the first mode of the second excitation mode, the polarity and level of the excitation current of the stepping motor are set in each of a pair of continuous two of the plurality of phase positions. At least one is different,
In the second mode of the second excitation mode, the polarity and level of the excitation current of the stepping motor are set in each of a group of four consecutive phase positions. At least one is different,
7. The motor control device according to claim 6, wherein in each of the first and second modes, the polarity and level of the exciting current of the stepping motor are set to be the same at each of the phase positions included in the same set. . In the deceleration section of the stepping motor, the first excitation mode is such that the first step angle of the first excitation mode is twice as large as the second step angle of the second excitation mode. 1, and at least one of a second mode in which the first step angle is four times the second step angle,
In the first mode of the first excitation mode, the polarity and level of the excitation current of the stepping motor are set for each of a pair of two consecutive phase positions. At least one is different,
In the second mode of the first excitation mode, the polarity and level of the excitation current of the stepping motor are set in each of a group of four consecutive phase positions. At least one is different,
In the second excitation mode, at each of the plurality of phase positions, at least one of the polarity and the level of the excitation current of the stepping motor is different,
In each of the first and second modes of the first excitation mode, the polarity and level of the excitation current of the stepping motor are set to be the same at each of the phase positions included in the same set. Item 7. The motor control device according to Item 6.

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